I ride a yz250 for everything, and when you get acquainted with your bike even a mx'er like a yz is easy to control in the woods with good throttle and clutch control.
If I were in your position, I would sell the kdx and use the money to either buy a 250 2stroke and either make it a bit more woods tame with a flywheel weight (or just leave it and really learn the bike), or I'd go with one of the ktm xc series bikes. A buddy of mine really likes his 300exc/e and it does pretty well everywhere, although I do have to say that the non-linkage definitely shows it's weakpoint on the track. That being said, if you're not planning on racing mx, it would be a great bike for your application.